1. Field of the Invention
The present invention relates generally to Power over Ethernet (PoE) and, more particularly, to a system and method for secure communication for PoE between a computing device and a switch.
2. Introduction
The IEEE 802.3af and 802.3at PoE specifications provide a framework for delivery of power from power sourcing equipment (PSE) to a powered device (PD) over Ethernet cabling. Various types of PDs exist, including voice over IP (VoIP) phones, wireless LAN access points, Bluetooth access points, network cameras, computing devices, etc.
In the PoE process, a valid device detection is first performed. This detection process identifies whether or not it is connected to a valid device to ensure that power is not applied to non-PoE capable devices.
After a valid PD is discovered, the PSE can optionally perform a power classification. In a conventional 802.3af allocation, each PD would initially be assigned a 15.4 W power classification after a Layer 1 discovery process. An optional classification process could then reclassify the PD to a lower power level. For example, a Layer 2 classification engine can be used to reclassify the PD. In general, a Layer 2 classification process can be included in PoE systems such as 802.3af, 802.3at or proprietary schemes.
In general, Layer 2 communication can be used to enable a determination of an amount of power to be allocated to a PD. Where a PD such as a computing device has rapidly changing power needs, the Layer 2 communication can be used to transmit various power management information relevant to the PD's current or anticipated needs. Examples of such power management information include battery information, computing device component information, external device information, user information, application information, or the like What is needed therefore is a mechanism for managing the PoE communication.